public class DefaultFaceletsStateManagementStrategy
extends StateManagementStrategy
This class implements partial state saving feature when facelets
is used to render pages. (Theorically it could be applied on jsp case too,
but all considerations below should be true before apply it).
The following considerations apply for this class:
1. This StateManagementStrategy should only be active if javax.faces.PARTIAL_STATE_SAVING
config param is active(true). See javadoc on StateManager for details.
2. A map using component clientId as keys are used to hold the state.
3. Each component has a valid id after ViewDeclarationLanguage.buildView().
This implies that somewhere, every TagHandler that create an UIComponent
instance should call setId and assign it.
4. Every TagHandler that create an UIComponent instance should call markInitialState
after the component is populated. Otherwise, full state is always saved.
5. A SystemEventListener is used to keep track for added and removed components, listen
PostAddToViewEvent and PreRemoveFromViewEvent event triggered by UIComponent.setParent()
method.
6. It is not possible to use javax.faces.component.visit API to traverse the component
tree during save/restore, because UIData.visitTree traverse all rows and we only need
to restore state per component (not per row).
7. It is necessary to preserve the order of the children added/removed between requests.
8. Added and removed components could be seen as subtrees. This imply that we need to save
the structure of the added components subtree and remove one component could be remove
all its children and facets from view inclusive.
9. It is necessary to save and restore the list of added/removed components between several
requests.
10.All components ids removed in any moment of time must be preserved.
11.Each component must be restored only once.
11.The order is important for ids added when it is traversed the tree, otherwise the algorithm
could change the order in which components will be restored.
- Since:
- 2.0
- Version:
- $Revision$ $Date$
- Author:
- Leonardo Uribe (latest modification by $Author$)